1. Field of the Invention
The invention relates to a humerus head prosthesis.
2. Description of the Prior Art
A humerus head prosthesis or shoulder prosthesis of this kind is known from the prior art. It has a head and a shaft. The head, which corresponds substantially to a spherical segment, can be releasably connected to the shaft via a neck. It has an eccentric bore for the neck. In humerus head prostheses there is the problem of the bone integration of the tubercles at the prosthesis. The previously known humerus head prosthesis offers no practicable and reliable help for this.
The object of the present invention is therefore to provide a humerus head prosthesis with an improved integration possibility of the tubercles.
The present invention provides a humerus head prosthesis that includes a hollow quiver arranged at the shaft and facilitates the integration of the tubercles at the prosthesis. It can be filled with bone shavings or bone splinters, with an ossification and a connection to or of the tubercles through the jacket openings being possible. In many cases of a shoulder lesion the tendon is still grown on at the tubercles, with the detachment having taken place in the bone. The tendons with the tubercles can then again be secured to the humerus head prosthesis and integrated via the ossification.
The jacket openings of the quiver also afford a possibility for the exact positioning and temporary securing of the tubercles at the anatomically correct location. For this purpose it is also provided in accordance with the invention that the quiver is arranged subcapitally at the level of the anatomical location of the tubercles and laterally at the shaft. The proximally lying filling-in opening facilitates the introduction of the bone shavings. The funnel-like quiver shape also facilitates this, with the funnel shape additionally assisting the anatomically correct positioning of the tubercles and in addition offering more bone matter in the proximal region for the growing on than in the distal region in an anatomically favorable manner.
In a particularly advantageous manner at least a portion of the jacket openings is provided with screw threads, which permit an exact positioning of the tubercles by means of bone screws. For improving the thrift it is advantageous in this to provide the threaded bore with a metric thread in order to be able to use economical standard screws with compression collars.